Inserting rapier for a rapier weaving machine

ABSTRACT

An inserting rapier ( 1 ) for a rapier weaving machine with a thread clamp ( 4 ) for the firm clamping of a weft thread ( 3 ) is presented, with the inserting rapier also including a guiding or holding device ( 10 ) with a guiding or holding element ( 5 ) and a mass ( 6 ) which are movably arranged on the inserting rapier and with the guiding or holding element ( 5 ) being movable by means of the inertia of the mass ( 6 ) in order to guide or hold the weft thread.

The invention relates to an inserting rapier for a rapier weavingmachine with a thread clamp for the firm clamping of at least one weftthread and to a method for guiding and holding a weft thread in aninserting rapier in accordance with the preamble of claim 8 and to aweaving machine with an inserting rapier of this kind and for carryingout a method of this kind.

In rapier weaving machines the weft thread is inserted into a shed bymeans of an inserting rapier, which is mounted on a bar or a flexibleband, and is taken over at a transfer point in the middle part of theshed by a receiving rapier and transported further. The inserting rapierhas the task of securely gripping the presented weft thread, to insertthe latter into the shed and to guide it precisely to the receivingrapier. An inserting rapier of this kind, which contains a thread guideformed in it and a thread clamp is for example disclosed in thepublication EP 0 441 099 A1.

In modern rapier weaving machines the inserting rapiers are moved athigh speed during the weft insertion. The inserting rapiers must bebraked from this high speed in order that the weft thread can be takenover by the receiving rapier at the transfer point. As a result of theinertial mass of the weft thread it can happen that the weft threadcontinues its movement at the transfer point so that the thread sectionto be taken over by the receiving rapier departs from its intendedposition and the receiving rapier can not grip the weft thread. In orderto reduce weft insertion errors of this kind a controlled thread brake,which brakes the forwardly moving weft thread, can be provided on theinsertion side in the region of the thread delivery apparatuses. Thedanger of the thread section to be taken over departing from itsintended position in the inserting rapier is however still present, inparticular in the case of heavy weft threads, even if a thread brakebrakes the weft thread, since the inertial forces which arise in thedeceleration of the weft thread stretch it elastically after the threadbrake.

The object of the invention is to make available an inserting rapier fora rapier weaving machine and a method for guiding and holding a weftthread in an inserting rapier which prevent running on of the weftthread at the transfer point and which enable the weft thread to beguided in such a manner that it can be reliably taken over by areceiving rapier.

This object is satisfied in accordance with the invention by theinserting rapier which is defined in claim 1 and by the method forguiding and holding a weft thread in a inserting rapier which is definedin claim 8 as well as through the weaving machine which is defined inclaim 10.

The inserting rapier in accordance with the invention for a rapierweaving machine comprises a thread clamp for the firm clamping of atleast one weft thread. In addition the inserting rapier comprises aguiding and/or holding device for guiding and/or holding the weft threadwith a guiding and/or holding element and a mass, with the guidingand/or holding element being controllable and/or movable by means ofinertial forces which act on the mass during an acceleration ordeceleration of the inserting rapier. In a preferred variant the guidingand/or holding element and/or the mass are movably mounted on theinserting rapier.

In a preferred embodiment the thread clamp and the guiding and/orholding element are arranged with spacing with respect to one another sothat during the transfer to a receiving rapier the weft thread can beguided and/or held at both sides of the receiving rapier. In a preferredvariant the inserting rapier comprises two side walls, with the threadclamp being arranged in the vicinity of the one side wall and theguiding and/or holding element in the vicinity of the second side wall.

In a further preferred embodiment the guiding and/or holding element isresiliently designed, secured or mounted, or connected to a springelement, and the mass is arranged at the guiding and/or holding element;and in an additional preferred embodiment the guiding and/or holdingelement is designed as a movably journalled pawl, with it being possiblefor the mass to be part of the pawl, so that the latter can be moved bymeans of the inertia of its own mass.

In a preferred variant the guiding and/or holding element is designedand arranged such that the weft thread can be held by the former in anotch which is formed in the inserting rapier, in particular in an upperpart of the inserting rapier.

Furthermore, the invention comprises a method for guiding and holding aweft thread in an inserting rapier, in which the weft thread is taken upby the inserting rapier and is clamped firmly in the latter by means ofa thread clamp, with the weft thread additionally being guided and/orheld in the inserting rapier by means of a guiding and/or holding devicewhich is controlled and/or moved by means of the inertia of a mass.

In a preferred embodiment of the method the guiding and/or holdingdevice is closed by the inertia of the mass prior to reaching thetransfer point, so that the weft thread extends between the thread clampand the guiding and/or holding device on reaching the transfer point andthe weft thread, which extends between the thread clamp and the guidingand/or holding device, is taken over by a receiving rapier.

Furthermore, the invention comprises a rapier weaving machine with aninserting rapier in accordance with any one of the above describedembodiments and/or equipped for carrying out a method in accordance withthe above description.

The inserting rapier in accordance with the invention and the method inaccordance with the invention for guiding and holding a weft thread inan inserting rapier have the advantage that thanks to the additionalguiding and/or holding device, which can be controlled by means ofinertial forces, a high reliability can be achieved in the threadtransfer from the inserting rapier to the receiving rapier. This isparticularly important in the case of rapid weft insertions, which canfor example amount to 350 insertions/min or 500 insertions/min or more.If the weft runs ahead, this takes place outside the thread transferregion, so that the running ahead hardly causes a disturbance in thethread transfer. Thanks to the additional guiding and/or holding devicethe weft thread need only be minimally braked at most during the threadtransfer, so that most of the weft threads can be inserted without acontrolled thread brake. It is particularly advantageous that the weftthread can be fixed more firmly in the receiving rapier, since therequired thread tension is ensured on both sides through the holding ofthe weft thread on both sides of the receiving clamp. It is furthermoreadvantageous that the danger of the weft thread being overstretched whenbeing hung into the receiving rapier is slight, since the basic tensioncan be kept low.

The above description of embodiments serves merely as an example.Further advantageous embodiments result from the independent claims andthe drawings. Moreover, in the context of the present inventionindividual features from the described or illustrated embodiments andvariants can also be combined with one another in order to form newembodiments.

The invention will be explained in the following in more detail withreference to the exemplary embodiment and with reference to thedrawings. Shown are:

FIG. 1 a perspective view of an exemplary embodiment of an insertingrapier in accordance with the present invention together with areceiving rapier,

FIG. 2A an enlarged perspective view of the same exemplary embodimentwith an inserted weft thread and open guiding and/or holding device,

FIG. 2B a perspective view of the exemplary embodiment which is shown inFIG. 2A with a closed guiding and/or holding device,

FIG. 3A a perspective view of a second exemplary embodiment with aninserted weft thread and open guiding and/or holding device, and

FIG. 3B a perspective view of the exemplary embodiment which is shown inFIG. 3A with a closed guiding and/or holding device.

FIG. 1 shows an exemplary embodiment of an inserting rapier inaccordance with the present invention together with a receiving rapier 2in a perspective view. The weft insertion direction is marked with anarrow 12 in FIG. 1. In the illustrated embodiment the inserting rapier 1comprises a thread clamp 4 for firmly clamping at least one weft threadas well as additionally a guiding and/or holding device 10 for guidingand/or holding the weft thread and having a guiding and/or holdingelement 5 and a mass 6. The guiding and/or holding element 5 iscontrollable and/or movable by means of inertia forces which act on themass 6 during an acceleration or deceleration of the inserting rapier 1.In an advantageous embodiment the guiding and/or holding element 5and/or the mass 6 are movably mounted on the inserting rapier. Thedesign and method of action of the guiding and/or holding device 10 willbe explained in more detail in connection with the descriptions of FIGS.2A, 2B and 3A, 3B.

In a further advantageous embodiment the inserting rapier 1 can comprisefurther parts, for example, as shown in FIG. 1, two side walls 1 a, 1 band where required an upper part 9. The upper part can, as shown, beprovided with a notch 8 into which the weft thread can be laid in orderto be able to guide the latter during the insertion. Furthermore, theguiding and/or holding element 5 can be mounted on the upper part 9, forexample by means of a mounting element 7, which can e.g. be executed asa screw.

In a preferred embodiment the thread clamp 4 and the guiding and/orholding element 5 are arranged with spacing with respect to one another,so that the weft thread can be guided or held on both sides of thereceiving rapier during the transfer to the receiving rapier. If theinserting rapier 1 includes two side walls 1 a, 1 b the thread clampcan, for example, be arranged in the vicinity of the one side wall andthe guiding and/or holding element can be arranged in the vicinity ofthe second side wall.

FIG. 2A shows an enlarged perspective view of the same exemplaryembodiment with a laid in weft thread and an open guiding and/or holdingdevice. In this exemplary embodiment the inserting rapier 1 comprises athread clamp 4 and in addition a guiding and/or holding device 10 whichis arranged with a spacing with respect to the thread clamp. In thisembodiment the guiding and/or holding device 10 contains a guidingand/or holding element 5 which is designed to be resilient, for examplein an advantageous variant as a bending spring which is secured at oneend to the inserting rapier, e.g. with a mounting means 7 at an upperpart 9 of the inserting rapier. The other end of the guiding and/orholding element 5, i.e. of the bending spring, is free and is deflectedin the position which is shown in FIG. 2A toward the thread clamp 4 tosuch an extent that the weft thread 3 can slide past the guiding and/orholding element 5 and for example be laid into a notch 8 in the upperpart 9. Furthermore, the guiding and/or holding device 10 contains amass 6, which can for example consist of the mass of the spring element5 or, in the event that the latter is too light, of an additional masswhich is arranged on the spring element. Particularly advantageous inthis variant is that the free end of the guiding and/or holding element5 can be moved without friction.

The inserting rapier which is shown in FIG. 2B differs from that in FIG.2A only in the position of the guiding and/or holding element 5. Thefree end of the guiding and/or holding element 5, which is designed as abending spring, is deflected in FIG. 2B in the direction toward a notch8 which is arranged laterally in the inserting rapier 1, so that thefree end closes off the notch, for example in that the guiding and/orholding element 5 makes contact with one side of the notch or protrudesbeyond the one side. A weft thread 3 which is laid into the notch isthus closed in, even if the thread section which extends outside theinserting rapier advances past the inserting rapier, as is indicated bya forwardly directed loop in FIG. 2B. Together with the notch 8, theguiding and/or holding element 5 thus forms a guiding eye. The guidingand/or holding element 5 can optionally also be formed as part of athread clamp, for example. The weft thread 3 is firmly held by thethread clamp 4 on the side of the inserting rapier which lies oppositeto the notch 8 or to the guiding eye respectively, so that the weftthread is held at both sides of the inserting rapier. Thanks to the mass6 which is arranged at the guiding and/or holding element 5, the freeend of the latter can be laterally deflected by the inertial forceswhich arise during the acceleration and deceleration of the insertingrapier; and the notch 8 or the guiding eye respectively can be opened orclosed.

FIG. 3A shows a perspective view of a second exemplary embodiment with alaid in weft thread and an open guiding and/or holding device. In theillustrated embodiment the inserting rapier 1 comprises a thread clamp 4as well as additionally a guiding and/or holding device 10 which isarranged with a spacing with respect to the thread clamp. In thisexemplary embodiment the guiding and/or holding device 10 contains amovably mounted pawl 5 which is for example pivotally journalled about amounting element 5 a. Furthermore, an abutment 5 b can be provided inorder to be able to limit the rotational movement on opening the pawl.The illustrated pawl comprises a closing part, which is pivoted towardthe thread clamp 4 in the position which is shown in FIG. 3A to such anextent that the weft thread 3 can slide past the closing part and forexample be laid into a notch 8 in an upper part 9 of the insertingrapier 1. In an advantageous variant the pawl 5 has sufficient mass toovercome the journalling friction, so that the pawl is movable by theinertial forces which act on the mass during the acceleration anddeceleration of the inserting rapier. Where required the pawl can alsobe connected to a spring element, for example in order to be able tokeep the pawl 5 open during slow movements of the inserting rapier.

The inserting rapier which is shown in FIG. 3B differs from that whichis shown in FIG. 3A only in the position of the pawl 5. The illustratedpawl comprises a closing part, which is pivoted in FIG. 3B in thedirection toward a notch 8 which is arranged laterally in the insertingrapier 1, so that the closing part closes off the notch, for example inthat it makes contact with one side of the notch or protrudes beyond theone side. A weft thread 3 which is laid in into the notch is thus closedin, even if the thread section which extends outside the insertingrapier moves on forwardly relative to the inserting rapier. Togetherwith the notch 8 the closing part of the pawl 5 forms a guiding eye. Onthe side of the inserting rapier which lies opposite to the notch 8 orto the guiding eye the weft thread 3 is held firmly by the thread clamp4, so that the weft thread is held on both sides of the insertingrapier. Thanks to the inherent mass of the pawl 5 the latter can bepivoted by the inertial forces which arise on acceleration anddeceleration of the inserting rapier, and the notch 8 or the guiding eyecan be opened and/or closed.

An exemplary embodiment of the method in accordance with the inventionfor guiding and holding a weft thread in an inserting rapier will bedescribed in the following with reference to FIGS. 2A and 2B. In thismethod the weft thread 3 is taken up by the inserting rapier 1 andclamped firmly in the latter by means of a thread clamp 4. For this theweft thread which is presented can for example be taken up by theinserting rapier at the beginning of the weft insertion, with the weftthread being drawn into the thread clamp and clamped firmly therein bythe forward movement of the inserting rapier. On the taking up of theweft thread by the inserting rapier the former can, if desired, also belaid into a guide in the inserting rapier which is arranged with spacingwith respect to the thread clamp 4, for example, as shown in FIG. 2A,into a notch 8. In this method the weft thread 3 is additionallycontrolled and/or held in the inserting rapier 1 by means of a guidingand/or holding device 10 which is controlled and/or moved by means ofthe inertia of a mass 6.

In an advantageous embodiment of the method the inserting rapier 1 isdecelerated prior to reaching the transfer point, with the guidingand/or holding device 10 being closed by the inertial forces which acton the mass 6, so that the weft thread 3 extends between the threadclamp 4 and the guiding and/or holding device 10 on reaching thetransfer point, as is shown in FIG. 2B. The weft thread, which extendsbetween the thread clamp and the guiding and/or holding device, is nowtaken over by a receiving rapier. The guiding and/or holding device 10is expediently designed such that the weft thread can be drawn out whenthe guiding and/or holding device is closed. In this way it can beensured that a thread tension is present on both sides of the receivingclamp during the transfer of the weft thread.

It is advantageous that the inertia controlled guiding and/or holdingdevice is necessarily open during the taking up of the weft thread atthe beginning of the weft insertion due to the positive accelerationwhich is present in this phase. Only in the event of very slow rapiermovements can it be expedient to ensure the opening of the guidingand/or holding device through additional measures, for example by aspring element.

Thanks to the additional guiding and/or holding device, which iscontrollable by means of inertia forces, a high reliability can beachieved in the thread transfer from the inserting rapier to thereceiving rapier, in particular also in the case of rapid weftinsertions. If running on of the weft thread arises, this takes placeoutside the thread section which extends between the thread clamp andthe guiding and/or holding device, so that the advance hardly representsa disturbance during the thread transfer.

In addition the risk is slight that the weft thread will beoverstretched when being hung in place at the receiving rapier, sincethe basic tension can be kept low. A further advantage is that the weftthread need only be minimally braked at most during the thread transfer,so that most of the weft threads can be inserted without a controlledthread brake, and that the weft thread can be better fixed in thereceiving clamp, since the weft thread is held on both sides of thereceiving rapier during the transfer and thus a tensile force is presenton both sides.

1. Inserting rapier for a rapier weaving machine with a thread clamp (4)for the firm clamping of at least one weft thread (3), characterized inthat the inserting rapier (1) also includes a guiding and/or holdingdevice (10) for guiding and/or holding the weft thread with a guidingand/or holding element (5) and a mass (6); and in that the guidingand/or holding element (5) can be controlled and/or moved by means ofinertial forces which act on the mass (6) during an acceleration ordeceleration of the inserting rapier.
 2. Inserting rapier in accordancewith claim 1, with the guiding and/or holding element (5) and/or themass (6) being movably mounted on the inserting rapier (1).
 3. Insertingrapier in accordance with claim 1, with the thread clamp (4) and theguiding and/or holding element (5) being arranged spaced apart in orderto be able to guide and/or to hold the weft thread (3) on transfer to areceiving rapier on both sides of the receiving rapier (2).
 4. Insertingrapier in accordance with claim 2, with the inserting rapier (1)including two side walls (1 a, 1 b) and with the thread clamp (4) beingarranged in the vicinity of the one side wall and the guiding and/orholding element (5) being arranged in the vicinity of the other sidewall.
 5. Inserting rapier in accordance with claim 1, with the guidingand/or holding element (5) being resiliently designed or mounted orbeing connected to a spring element, and with the mass (6) beingarranged at the guiding and/or holding element (5).
 6. Inserting rapierin accordance with claim 1, with the guiding and/or holding elementbeing designed as a movably journalled pawl (5) which can be moved bymeans of the inertia of its own mass.
 7. Inserting rapier in accordancewith claim 1, with the guiding and/or holding element (5) being designedand arranged in such a manner that the weft thread (3) is held by thesame in a notch (8) which is formed in the inserting rapier (1), inparticular in an upper part (9) of the inserting rapier.
 8. Method forthe guiding and holding of a weft thread in an inserting rapier, in saidmethod the weft thread (3) being taken up by the inserting rapier (1)and being clamped in the latter by means of a thread clamp (4),characterized in that the weft thread is additionally guided and/or heldin the inserting rapier by means of a guiding and/or holding device (10)which is controlled and/or moved by means of the inertia of a mass (6).9. Method in accordance with claim 8, with the guiding and/or holdingdevice (10) being closed by the inertia of the mass (6) prior toreaching the transfer point, with the weft thread (3) extending betweenthe thread clamp (4) and the guiding and/or holding device (10) onreaching the transfer point, and with a receiving rapier (2) taking overthe weft thread which extends between the thread clamp and the guidingand/or holding device.
 10. Rapier weaving machine including an insertingrapier in accordance with claim
 1. 11. Rapier weaving machine equippedfor carrying out a method in accordance with claim 8.